1. Technical Field
The present invention relates to a system and method for controlling an air supply of a fuel cell vehicle, and more particularly, to a method for controlling an air supply of a fuel cell vehicle capable of improving fuel efficiency by calculating the actual amount of air supply required, based on available power which may be currently used in a vehicle.
2. Description of the Related Art
A fuel cell vehicle includes a fuel cell stack in which a plurality of fuel cells used as a power source are stacked sequentially, a fuel supply system configured to supply hydrogen, and the like, as a fuel to the fuel cell stack, an air supply system configured to supply oxygen as an oxidizing agent required for electrochemical reaction, and a water and heat management system configured to control a temperature of the fuel cell stack, and the like.
In particular, the fuel supply system decompresses compressed hydrogen within a hydrogen tank to supply the decompressed hydrogen to an anode of the stack and the air supply system actuates an air blower to supply external air to a cathode of the stack.
When hydrogen is supplied to the anode of the stack and oxygen is supplied to the cathode, hydrogen ions are separated by catalytic reaction in the anode. The separated hydrogen ions are delivered to a negative electrode, (i.e., the cathode), through an electrolyte membrane and the hydrogen ions and electrodes separated in the anode electrochemically react with oxygen in the negative electrode, thereby obtaining electric energy.
A portion of the electric energy generated in the fuel cell stack may be used as a power source of a driving motor through an inverter and may be used to charge a high voltage battery through a converter.
When positions of an accelerator pedal, a braking pedal, a gear, and the like are input to a controller, the controller may issue a command to a motor control unit to control a driving motor, in which the motor control unit controls a speed and a torque of the driving motor accordingly.
Typically, an air supply control of the fuel cell vehicle is performed by calculating a torque for a driver's acceleration request based on power. In this case, an air supply quantity larger than the currently available power is required, which may lead to reductions in fuel efficiency and performance.